Commit 173431b2 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: defrag: reject unknown flags of btrfs_ioctl_defrag_range_args 



Add extra sanity check for btrfs_ioctl_defrag_range_args::flags.

This is not really to enhance fuzzing tests, but as a preparation for
future expansion on btrfs_ioctl_defrag_range_args.

In the future we're going to add new members, allowing more fine tuning
for btrfs defrag.  Without the -ENONOTSUPP error, there would be no way
to detect if the kernel supports those new defrag features.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: default avatarFilipe Manana <fdmanana@suse.com>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 3324d054

fs/btrfs/ioctl.c

+4 −0
Original line number Diff line number Diff line
@@ -2602,6 +2602,10 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp) 
				ret = -EFAULT;

				goto out;

			}

			if (range.flags & ~BTRFS_DEFRAG_RANGE_FLAGS_SUPP) {

				ret = -EOPNOTSUPP;

				goto out;

			}

			/* compression requires us to start the IO */

			if ((range.flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {

				range.flags |= BTRFS_DEFRAG_RANGE_START_IO;

include/uapi/linux/btrfs.h

+3 −0
Original line number Diff line number Diff line
@@ -614,6 +614,9 @@ struct btrfs_ioctl_clone_range_args { 
 */

#define BTRFS_DEFRAG_RANGE_COMPRESS 1

#define BTRFS_DEFRAG_RANGE_START_IO 2

#define BTRFS_DEFRAG_RANGE_FLAGS_SUPP	(BTRFS_DEFRAG_RANGE_COMPRESS |		\

					 BTRFS_DEFRAG_RANGE_START_IO)



struct btrfs_ioctl_defrag_range_args {

	/* start of the defrag operation */

	__u64 start;